Connector



" March 18, 1969 I 5. WALTER CONNECTOR ArV/IA/ Filed July 20, 1967 United States Patent O 3,434,091 CONNECTOR George Walter, Chicago, Ill., assignor to Malco Manufacturing Company, Inc, Chicago, Ill., a corporation of Illinois Fiied July 20, 1967, Ser. No. 654,727

US. Cl. 33914 Int. Cl. Hlllr 3/06; H02b 1/02 3 Claims ABSTRACT OF THE DISCLOfaURE Background of the invention This invention relates in general to electrical circuitry. It deals more particularly with an electrical connector assembly of the type including a plurality of wire-wrap type connectors mounted on a terminal plate.

The development of plate mounted connector assemblies including wire-wrap connectors for effecting direct entry connection with printed circuit boards gave rise to certain problems. One such problem arose because this connector assembly design requires that one or more contacts in a connector pattern be capable of making a highly reliable electrical connection with the aluminum plate upon which the contacts and insulators are mounted. The plate is then used as a ground plate, i.e., part of the electrical circuit.

At first, a number of the readily available, conventional ground connectors were tried. The conventional: connectors employ press fit metal bushings encircling the contacts and seated in the apertures in the terminal plate, for example, or various forms of clips. None of the known ground connectors were found to make a sufiiciently reliable connection to the plate, however.

Furthermore, these ground connectors were difficult to remove and replace without damaging adjacent components.

Accordingly, it is an object of the present invention to provide a new and improved ground connector assembly for completing an electrical connection between a plate mounted contact and the plate.

It is another object to provide a ground connector assembly which makes a consistently reliable connection between a wire-wrap post type connector and the metal plate on which it is mounted.

It is still another object to provide a ground connector assembly of the aforedescribed character which is simple and inexpensive in construction, and occupies minimal space on a terminal connector module.

It is yet another object to provide a ground connector assembly which permits simple and expeditious removal and replacement of the contact from the terminal plate.

It is a further object to provide a ground connector assembly which assures a gas tight connection between the connector and the terminal plate so that corrosion cannot take place on mating surfaces between the connector and plate, and cause a high resistance connection.

The foregoing and other objects are realized in accord with the invention by providing a ground connector assembly including a ground sleeve which encases a contact. The contact is preferably of the type which has a wire-wrap tail on one end for connection to wire leads 3,434,091 Patented Mar. 18, 1969 by conventional wire-wrap techniques. The ground sleeve extends through a suitably formed aperture in a terminal plate formed of aluminum or the like and is anchored to the plate by a ground nut. The ground nut threads onto the lower end of the ground sleeve and bites into the lower surface of the board or plate surrounding the sleeve, forcing the plate material inwardly to form a gas tight connection between the sleeve, the plate, and the nut.

The invention, together with its organization and method of operation, taken with further objects and advantages thereof, is illustrated more or less diagrammatically in the drawing, in which:

FIGURE 1 is a diagrammatic plan view of a portion of a connector complex mounted on a terminal plate, wherein the connector complex includes a ground connector assembly embodying features of the present invention;

FIGURE 2 is an enlarged sectional view taken along line 22 of FIGURE 1, with parts broken away; and

FIGURE 3 is an enlarged sectional view similar to FIGURE 2 with the section taken ninety degrees from that of FIGURE 2.

Referring now to the drawing, and particularly to FIGURE 1, a portion of a connector complex is illustrated generally at 10, mounted on a conventional aluminum terminal plate 11. The connector complex includes a matrix of dielectric material such as phenolic or the like. The phenolic matrix 20 actually comprises a series of elongated printed circuit board receiving blocks 20a, et seq. (only a portion of one shown) arranged in immediately adjacent, side-by-side relationship on the terminal plate 11. Each elongated block 20a, et seq. is adapted to receive one printed circuit board in the manner illustrated in the co-pending Walter application, Ser. No. 645,843, filed July 20, 1967, entitled Buss Strip, and assigned to the same assignee as the present invention.

Only a portion of the block 20a is illustrated as has been pointed out. The block 20a actually includes a pair of oppositely disposed end block segments 21 (only one shown) separated by a plurality of intermediate block segments 22 (only one shown). Each of the block segments 21 and 22 houses a plurality of electrical contacts adapted to engage circuitry on a printed circuit board inserted into the matrix block 20a.

Of the contacts 30 mounted in the block segments 21 and 22, the two intermediate contacts 30a in each end block segment 21 are distinctive as components of buss strip and contact arrangements embodying features of an invention disclosed in the aforementioned co-pending Walter application. These buss strip and contact arrangements 35 carry current to circuitry on respective printed circuit boards through the contacts 30a.

On the other hand, the end contact 3012 in the block segment 21 illustrated is part of a ground connector assembly embodying features of the present invention. The ground connector assembly 40 is adapted to make electrical connection between circuitry on the printed circuit board (not shown), through the contact 30b, to the terminal plate 11. According to the invention this ground connection is a highly reliable, low resistance, gas-tight connection. Furthermore, the ground connector assembly 40 shown in FIG. 2 is extremely compact so that it does not interfere with other circuitry components on the terminal plate and readily facilitates removal and replacement of the contact 30b without disturbing adjacent circuitry components.

In FIGURES 2 and 3, the ground connector assembly 40 is illustrated in substantial detail. The connector assembly 40 is mounted on the plate 11 in a well (only one side shown) in the matrix block segment 21. The matrix block segment 21 is seated on the upper surface 66 of the terminal plate 11. The matrix block segment 21 is secured to the plate 11 in the manner described in the aforementioned pending Walter application.

The ground connector assembly includes the con tact 30b which is an arcuate, flexible spring type contact formed unitarily with a wire-wrap connector pin 70. The connector pin has the contact 3011 formed unitarily on one end, and a wire-wrap post 71 on its opposite end.

Intermediate the contact 30b and wire-wrap post 71 of the pin 70 is a relatively wide base section 73. The contact 30b forms the free end of the base section 73. The base section 73 is necked down opposite the contact 30b, as at 74, to a narrower guide section 75. The guide section 75 is, in turn, necked down at 76. Spaced a short distance from the guide section 75 on the wire-wrap post 71 are guide shoulders having inclined leading faces 81.

The guide shoulders 80 and the guide section 75 are designed to properly center the pin 70 in a generally circular cylindrical connector sleeve 84. The connector sleeve 84 has an elongated, generally circular cylindrical passage 85 extending through it into which the pin 70 is inserted. The passage 85 includes an upper passage section 86 having a diameter that will make a slip fit to the base section 73 on the pin 70, and a lower passage section 87 having a diameter that will make a press fit to the guide shoulders 80 and guide section 75 on the pin. The passage sections 86 and 87 are joined at an inclined shoulder 88.

The function of the guide shoulders 80 and guide section 75 will now be recognized. As the terminal pin 70 is inserted in the passage 86 through the sleeve 84, the inclined surfaces 81 on the shoulders 80 engage the inclined shoulder 88 in the passage, forcing the wire-wrap post 71 into centered relationship in the passage section 87. As the pin 70 continues to be inserted, the guide section 75 functions in the same manner. Since the width of the shoulders 80 and the guide section 75 is slightly greater than the diameter of the passage section 87, the pin is lightly but snugly held in centered relationship in the sleeve 84 at any preselected depth of insertion into the sleeve. At this point, the post 71 extends a predetermined distance out of the sleeve 84.

With the pin 70 inserted in the sleeve 84 in the manner hereinbefore described, the sleeve is anchored to the pin 70 by soldering. In the ground connector assembly 40 illustrated, solder is introduced to the passage 85 around the pin 70 and allowed to fill the passage to make a solid, electrically conductive connection between the pin and the sleeve 84. Although soldering of the pin 70 to the sleeve 84 is illustrated, however, and is presently considered preferable, it is conceivable that the pin might be fixed in the sleeve by other techniques such as crimping, or welding, for example.

The sleeve 84 itself includes a square cross section housing section 91 and a circular cylindrical mounting section 92 separated by a shoulder 93. The diameter of the mounting section 92 is substantially identical to or only slightly less than the diameter of a corresponding plate aperture 94 into which the sleeve 84 is inserted. The sleeve 84, with the pin 70 anchored within it, is inserted into the aperture 94 through the square crosssection matrix block segment well 65 until the shoulder 93 engages the upper surface 66 on the plate 11, in which position approximately one-half of the mounting section 92 extends below the lower surface 95 of the plate 11. As seen in FIGURE 1, the pin 70 and contact 30b are automatically orientated properly by the complementary relationship of the square housing section 91 and the square Well 65.

That portion of the mounting section 92 which extends below the plate 11 is externally threaded as at 96. The external threads 96 are adapted to cooperate with internal threads 97 formed in a locking nut 98 until the nut tightly engages the lower surface 95 of the plate 11 to draw the sleeve shoulder 93 tightly into engagement with the upper surface 66 of the plate.

The nut 98 engages the lower surface 95 of the plate 11 with its entire annular sealing end 100. The sealing end 100 of the nut 98 includes a frusto-conical surface 101 terminating in a relatively thin, semi-sharp peripheral edge 102. As the nut 98 is turned onto the sleeve threads 96, the peripheral edge 102 bites into the lower surface 95 of the plate 11. The frusto-conical surface 101 displaces plate material slightly inwardly. An extremely secure, gas-tight joint is thus created between the nut 98 and the plate 11, with the threads 96, 97 creating a similar connection between the sleeve 84 and the nut 98. Accordingly, harmful gases cannot seep between the nut and the plate 11 to cause corrosion and increased resistance to current flow.

The nut 98 includes an octagonal head 105 which facilitates gripping the nut to turn it on the sleeve threads 96. The entire nut 98 with the head 105 is, nevertheless, extremely compact, and can readily be removed and replaced with a slim, socket-type wrench which fits over the Wire-wrap post 71. Accordingly, interference with adjacent electrical circuitry components is easily avoided.

A simple but highly effective ground connector assembly 40 has now been shown. It is easy to mount, remove, and replace contacts employed with it without disturbing adjacent circuitry components. In this light, although a spring type contact 30b of the type utilized to engage a printed circuit board has been shown, the ground connector assembly is also readily adaptable to use with female fork type terminals or the like, as well as other contacts and terminals.

While the embodiment described herein is at present considered to be preferred, it is understood that various modifications and improvements may be made therein.

What is desired to be claimed and secured by Letters Patent of the United States is:

1. A ground connector assembly for making a ground connection between a conductor and a metallic terminal plate, comprising:

(a) a terminal connector pin having a wire-wrap post at one end,

(b) a sleeve having an axially extending passage therethrough,

(c) guide means on at least one of said passage and said pin for centering said pin in said sleeve,

(d) means in said passage securing said pin in said sleeve and making an electrical connection between said pin and said sleeve,

(c) said sleeve including a mounting section extending through an aperture in the terminal plate whereby said wire-wrap post also extends through the plate,

(f) shoulder means on one end of said mounting section,

(g) external threads formed on at least a portion of said mounting section,

(h) an internally threaded locking nut threaded onto said mounting section external threads into engagement with the plate opposite said shoulder to draw said shoulder tightly against the plate and complete an electrical connection between the plate, said nut and said sleeve,

(i) said nut including a sealing end having an edge formed thereon which bites into a corresponding surface of said plate.

2. The ground connector assembly of claim 1 further characterized in that:

(a) said means securing said pin in said sleeve comprises solder in the space between said pin and the wall of said passage.

3. The ground connector assembly of claim 1 further characterized in that:

(a) said sleeve includes a housing section of polygonal cross-section external configuration to properly orient 6 the sleeve by engagement with the dielectric matrix 3,163,709 12/1964 Fox 339-17X in which it is adapted to be seated, 3,200,366 8/ 1965 Stuart 339--130 (b) said mounting section having a circular cylindrical 3,351,891 11/1967 Schneck 339'276 cross-section external configuration.

FOREIGN PATENTS 5 References (31ml 748,094 4/1933 France. UNITED STATES PATENTS RICHARD E. MOORE, P E 1,976,077 10/1934 Lind'berg et al. 151-37 xammer 2,321,510 6/1943 Paqllette 339-130X 10 US, Cl. X.R.

2,995,617 8/1961 Maximoif et a1. 339221 X 339-430 

